1. Field of the Invention
The present invention relates to an apparatus and method of utilizing a sleeve as both a fluid bearing and for creating an interference fit with a shaft. Once the interference fit is created with the shaft, the position of the shaft is adjusted to change the stroke length of a slide in a press.
2. Description of the Related Art
Adjusting the stroke length of a slide in a press is a function that is necessary depending on the type of material being pressed, as well as, the resulting desired shape of the material after the press stroke. One way of adjusting the slide is by utilizing a lever. The lever is inserted into a bore located within a flywheel. The bar is moved up or down to manually rotate the flywheel causing the stroke length to be adjusted. Two people are required to adjust the slide in this manner. One person moves the bar up and down while the second person tells the first person when the slide is in the proper position. This method of adjusting the slide is very inefficient as two people are needed to adjust the slide and those two people are not doing other aspects of their jobs while they are adjusting the slide. Also, this method of adjusting the slide is very imprecise because the second person""s view is blocked by the first person adjusting the stroke length of the slide.
Another way of adjusting the slide is to intermittently engage the clutch while the flywheel is spinning to move the slide to the desired position. This method of adjusting the slide is very imprecise because of the difficulty of moving the slide in small increments. Also, engaging and disengaging of the clutch so often causes the clutch and the brake pads to wear quickly, as well as, possibly warp from the heat. The present invention solves these problems.
The present invention, in one form thereof, is a press having a housing wherein a shaft and a sleeve are disposed within the housing. A pressure means is in fluid communication with the sleeve for selectively supplying fluid pressure to the sleeve to create an interference fit between the sleeve and the shaft. The pressure means reduces fluid pressure to the sleeve to release the interference fit between the sleeve and the shaft wherein the sleeve works as a fluid bearing. An adjustment means is connected to the housing for adjusting the position of the shaft when the interference fit exists between the sleeve and the shaft.
The present invention, in another form thereof, is a press having a housing wherein a shaft and a sleeve are disposed within the housing. A pressure means is in fluid communication with the sleeve for supplying fluid pressure to the sleeve to create an interference fit between the sleeve and the shaft. The pressure means reduces fluid pressure to the sleeve to release the interference fit between the sleeve and the shaft wherein the sleeve works as a fluid bearing. An adjustment mans is connected to the housing for moving the housing to adjust the position of the shaft when the interference fit exists between the sleeve and the shaft.
The present invention, in yet another form thereof, is a method of adjusting the position of the shaft in a press. The first step of the method is providing a shaft and sleeve. The next step of the method is applying fluid pressure to the sleeve to create an interference fit between the sleeve and the shaft. The final step of the method is adjusting the position of the shaft when the interference fit exists between the sleeve and the shaft.
An advantage of the present invention is that a computer can be used to activate the adjustment of the position of the shaft which thereby adjusts the stroke length of the slide. By having the computer adjust the rotation of the shaft, the workers can perform other tasks to be more cost effective.
Another advantage of the present invention is that the apparatus used to adjust the rotation of the shaft allows for very precise adjustments to the stroke position of the slide without excess wear to the clutch or brake pads.